Technical Field
The present invention relates to a lens driving apparatus, and more particularly, to a lens driving apparatus with a wire accommodating recess.
Description of Related Art
In recent years, camera modules have been applied to various devices, and more particularly to portable devices. Optical imaging stabilization (OIS) lens modules and voice coil motor (VCM) lens modules have increasingly been installed in portable devices to serve as webcams, imaging lenses, and etc. An OIS lens module enables an adjustment in an imaging path of a view-taking lens via the active mechanism thereof so as to stabilize the imaging formation performance under unstable environment while the VCM architecture provides the focusing function.
A VCM lens module mainly comprises a lens and a driving apparatus coupled to the lens. During the process in which the lens performs the imaging operation (i.e. an image is being projected onto a light sensing element), the distance measuring mechanism of the driving apparatus enables the driving apparatus to drive the lens according to different object distances so that the lens or lens elements in the lens (even other imaging components) will be forced to move to a proper position, thereby achieving the focusing effect.
The driving apparatus can have a variety of design configurations. For example, a driving apparatus can comprise a driving coil, a magnet, a Hall sensor and/or a control circuit, wherein the driving coil can be integrated into a lens (or integrated into a component linked to the lens), and the magnet can be disposed in proximity to, but not in contact with, the driving coil so that a magnetic field at least partially covers the driving coil. According to the design of a lens or the manner in which the driving force is presented, there are a variety of potential options for the contours, locations and numbers of the driving coil and the magnetic. The Hall sensor can be disposed at a proper location (e.g. on the lens) so as to sense a change in the magnetic field caused by the displacement of the lens. The control circuit transmits a driving signal to the driving coil based on the sensing result of the Hall sensor, thereby driving the lens with the generated electromagnetic force.
The abovementioned driving coil and control circuit are electrically connected. Generally, either an OIS lens module or a VCM lens module comprises at least one leaf spring disposed on a path along which the lens moves so as to limit a movable range of the lens and to provide buffering. The leaf spring is generally made of an electrically conductive material (e.g. metal), thus a signal may be transmitted from the control circuit to the driving coil via the leaf spring. An electrically conductive path between the driving coil and the leaf spring is established by welding one end of the wire from which the driving coil is formed to a contact pad on the leaf spring so as to form an electrical connection therebetween. The leaf spring is designed to reduce an impact on the lens. However, when the magnitude of an impact exceeds to a certain extent, the conjugate structure of the mechanically joined wire and leaf spring is insufficient to withstand an excessively large pulling force, as a result, the wire would break and disengage from the leaf spring. Therefore, the driving apparatus of the lens would break down due to a drastic impact.
In order to ensure the electrical connection between the driving coil and the leaf spring even when a drastic impact acts upon the driving apparatus of the lens, one of the problems to be solved relates to the manner in which the wire is connected and the design of the supporting mechanism.